1. Field of the Invention
This invention relates to a drainage system, more particularly to a drainage system including drainage pipes for directing surface water into soil areas of underground strata.
2. Description of the Related Art
Urbanization has caused replacement of permeable soil with impervious surfaces, such as pavements and buildings, which results in increase in surface runoff when rainwater falls on the impervious surfaces. Surface runoff may cause problems of water accumulation in low-lying land and debris flow. Therefore, a drainage system or a sewer system is required for draining of surface water into rivers or the sea so as to reduce surface runoff.
In addition, since an impervious surface seals a soil surface, and eliminates rainwater infiltration and groundwater recharge, the natural environment is adversely affected, such as the surface temperature adjusted by vegetation and soil is increased.